Hybrid spinach variety 51-710 rz

ABSTRACT

The present invention relates to a  Spinacia oleracea  seed designated 51-710 RZ, which exhibits a combination of traits including medium-late bolting, a semi-erect to horizontal plant habit, a smooth to semi-savoy leaf surface and resistance to downy mildew ( P. farinosa  f. sp.  spinaciae ) races Pfs1 to Pfs15. The present invention also relates to a  Spinacia oleracea  plant produced by growing the 51-710 RZ seed. The invention further relates to methods for producing the spinach cultivar, represented by spinach variety 51-710 RZ.

RELATED APPLICATIONS AND INCORPORATION BY REFERENCE

This application claims priority to U.S. provisional patent applicationSer. No. 62/096,082, filed Dec. 23, 2014.

The foregoing application, and all documents cited therein or duringtheir prosecution (“appln cited documents”) and all documents cited orreferenced in the appln cited documents, and all documents cited orreferenced herein (“herein cited documents”), and all documents cited orreferenced in herein cited documents, together with any manufacturer'sinstructions, descriptions, product specifications, and product sheetsfor any products mentioned herein or in any document incorporated hereinby reference, are hereby incorporated herein by reference, and may beemployed in the practice of the invention. More specifically, allreferenced documents are incorporated by reference to the same extent asif each individual document was specifically and individually indicatedto be incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to a new hybrid spinach (Spinaciaoleracea) variety which exhibits a combination of traits includingmedium-late bolting, a semi-erect to horizontal plant habit, a smooth tosemi-savoy leaf surface and resistance to downy mildew (P. farinosa f.sp. spinaciae) races Pfs1 to Pfs15.

BACKGROUND OF THE INVENTION

Spinach (Spinacia oleracea) is a flowering vegetable plant belonging tothe family Amaranthaceae. It is native to Southwestern and Central Asia,but today spinach is cultivated worldwide, mainly in temperate regions.Spinach plants are cultivated for their highly nutritious leaves. Theleaves are extremely rich in antioxidants, a good source of vitaminssuch as A, B6, C, E, K and folate, and minerals such as calcium, iron,magnesium and potassium.

The edible part of the spinach plant is a compact rosette shape ofleaves attached to a short stem. The leaves are produced during thefirst stage of the plant's life cycle, the vegetative rosette stage. Thesecond stage is the flowering stage, or the bolting stage. When boltingoccurs, there is growth of an elongated stalk with flowers growing fromwithin the main stem of the plant. Once the plant has reached thebolting stage, it is no longer possible to harvest marketable leaves.The plant will allocate its resources to flowering instead of leafproduction, which will ultimately cause the leaves to wither. Fastbolting is thus an undesired trait in the production of leafy vegetablessuch as spinach. Therefore, slower bolting is preferred by growers inorder to optimize yield.

There are three basic types of spinach, namely savoy, semi-savoy, andsmooth. The savoy type spinach has dark green, crinkly and curly leaves.The semi-savoy type spinach is a hybrid variety with slightly crinkledleaves. Smooth type spinach has broad, smooth leaves.

The leaves of a spinach plant are usually sold loose, bunched, inpre-packaged bags, canned or frozen. Each of these products requires itsown type of leaves. The smooth and some of the semi-savoy varieties arepredominantly used in processed products such as canned or frozenspinach, while the semi-savoy and savoy types are especially used forthe fresh market. Smooth leaf varieties are better suited for processingpurposes than semi-savoy and savoy varieties, because they are easier toclean and prepare for canning and freezing. Savoy leaf varieties, on theother hand, are preferred in the fresh market because the leaves packlooser than the smooth leaf varieties and are less likely to wilt orturn yellow.

The growth habit of spinach varieties can be classified in threedifferent categories, flat or prostate, semi-erect, and upright orerect. For mechanical harvest an upright or erect habit is preferred inorder to reduce soil contamination. Especially for varieties with savoytype leaves this is an important character, because the soil isdifficult to remove from curly leaves. Sometimes even plant growthregulators are applied before harvest to cause a more upright leafgrowth and reduce the risk of soil contamination. More upright varietiesare thus desired by growers to reduce contamination and costs forspraying plant regulators.

Downy mildew is probably the most widespread and potentially destructiveglobal disease of spinach. The causal agent of downy mildew on variousAmaranthaceae, including spinach, is regarded as a single species,Peronospora farinosa. In particular, Peronospora farinosa f. sp.spinaciae infects spinach. Initial symptoms of downy mildew consist ofdull to bright yellow necrotic lesions that appear on the leaves ofinfected spinach plants. With time the lesions can enlarge and becometan and dry. The infection can spread very rapidly, and it can occurboth in glasshouse cultivation and in soil cultivation, resulting inwidespread crop damage. In addition to the loss of quality of the leavesdue to the lesions, downy mildew can also cause breakdown and rot of theinfected leaves if they packaged in bags and cartons.

The optimal temperature for formation and germination of P. farinosa f.sp. spinaciae spores is 9 to 12° C., and it is facilitated by a highrelative humidity. When spores are deposited on a humid leaf surfacethey can readily germinate and infect the leaf. Fungal growth is optimalbetween 8 and 20° C. and a relative humidity of ≧80%, and within 6 and13 days after infection mycelium growth can be observed. Oospores of P.farinosa can survive in the soil for up to 3 years, or as mycelium inseeds or living plants. Although some fungicide treatments may beeffective, they are costly and cause ecological pollution.

In recent years various resistance genes have been identified thatprovide spinach plants with a resistance against downy mildew. However,it has been observed that previously resistant spinach cultivars canagain become susceptible to the fungus. Investigations revealed that thecultivars themselves had not changed, and that the loss of downy mildewresistance must therefore be due to P. farinosa overcoming theresistance in these spinach cultivars. The downy mildew races (alsocalled physios, isolates, or strains) that were able to infect resistantspinach cultivars were collected in a differential reference set, whichcan be used to test spinach cultivars for resistance. The differentialset may comprise a series of spinach cultivars (hybrids) that havedifferent resistance patterns to the currently identified pathogenicraces.

Currently there are 15 officially recognised races of Peronosporafarinosa f. sp. spinaciae, designated races Pfs 1 to Pfs15 (Irish et al.Phtypathol. Vol. 98 pg. 894-900, 2008; Plantum NL (Dutch association forbreeding, tissue culture, production and trade of seed and young plants)press release, “Benoeming van Pfs: 14, een nieuwe fysio van valsemeeldauw in spinazie”, Sep. 19, 2012; Report Jim Correl (Univ. Arkansas)and Steven Koike (UC Cooperative Extension, Monterey County), “Race Pfs:14—Another new race of the spinach downy mildew pathogen”, Sep. 18,2012; Plantum NL press release, “Denomination of Pfs: 15, a new race ofdowny mildew in spinach”, Sep. 2, 2014). Races 4 to 14 were identifiedbetween 1990 and 2012, while only recently another new Peronosporaisolate has been identified, termed UA4712, which subsequently has beenofficially named Pfs15 by the International Working Group on Peronospora(IWGP) (Plantum NL (Dutch association for breeding, tissue culture,production and trade of seed and young plants) press release,“Denomination of Pfs: 15, a new race of downy mildew in spinach”, Sep.2, 2014. All 15 officially recognized Pfs races are publicly availablefrom the Department of Plant Pathology, University of Arkansas,Fayetteville, Ark. 72701, USA, and also from NAK Tuinbouw, Sotaweg 22,2371 GD Roelofarendsveen, the Netherlands.

Newly identified Peronospora races can break the resistance of manyspinach varieties that are currently used commercially worldwide, andthey thus pose a serious threat to the productivity of the spinachindustry. For this reason new resistance genes are very valuable assets.In order to confer a resistance that is as broad as possible, i.e. thatconfers resistance to as many Pfs races as possible, preferable to allknown Pfs races, it is very useful to be able to stack differentresistance genes against Peronospora infection in spinach. This isachieved by stacking various resistance genes which have overlappingresistance patterns. In this way it becomes more difficult for thepathogen to overcome the resistance. Such a combination of differentresistance genes on one gene segment is also highly desirable. It ismuch easier if the resistance genes can be inherited as a singledominant loci, because in that case the resistance pattern that isconferred by the dominant resistance gene cannot segregate in theprogeny of the cross, and will always inherit as one single set ofresistances to various pathogenic races. One such resistance gene,designated R6, is a single dominantly inherited resistance gene inspinach that confers resistance to at least Peronospora farinosa f. sp.spinaciae races Pfs1, Pfs2, Pfs3, Pfs4, Pfs5, Pfs6, Pfs9, Pfs11, Pfs12,Pfs13 and Pfs14 (See generally U.S. application Ser. No. 13/774,633 andU.S. application Ser. No. 13/872,011).

Citation or identification of any document in this application is not anadmission that such document is available as prior art to the presentinvention.

SUMMARY OF THE INVENTION

There exists a need, therefore, for a hybrid spinach variety whichexhibits a combination of traits including medium-late bolting, asemi-erect to horizontal plant habit, a smooth to semi-savoy leafsurface and resistance to downy mildew (P. farinosa f. sp. spinaciae)races Pfs1 to Pfs15.

The present invention addresses this need by providing a new type ofspinach (Spinacia oleracea) variety, designated 51-710 RZ. Spinachcultivar 51-710 RZ exhibits a combination of traits includingmedium-late bolting, a semi-erect to horizontal plant habit, a smooth tosemi-savoy leaf surface and resistance to downy mildew (P. farinosa f.sp. spinaciae) races Pfs1 to Pfs15.

The present invention provides seeds of spinach cultivar 51-710 RZ,which have been deposited with the National Collections of Industrial,Marine and Food Bacteria (NCIMB) in Bucksburn, Aberdeen AB21 9YA,Scotland, UK and have been assigned NCIMB Accession No. 42336.

In one embodiment, the invention provides a spinach plant designated51-710 RZ, representative seed of which have been deposited under NCIMBAccession No. 42336, wherein said spinach plant may comprise acombination of traits including medium-late bolting, a semi-erect tohorizontal plant habit, a smooth to semi-savoy leaf surface andresistance to downy mildew (P. farinosa f. sp. spinaciae) races Pfs1 toPfs15.

In one embodiment, the invention provides a spinach plant designated51-710 RZ wherein said spinach plant may comprise a combination oftraits including medium-late bolting, a semi-erect to horizontal planthabit, a smooth to semi-savoy leaf surface, resistance to downy mildew(P. farinosa f. sp. spinaciae) races Pfs1 to Pfs15 and medium ovatemature leaves, representative seed of which have been deposited underNCIMB Accession No. 42336.

In one embodiment, the invention provides a spinach plant designated51-710 RZ, representative seed of which have been deposited under NCIMBAccession No. 42336.

In one embodiment, the invention provides a seed of a spinach plantdesignated 51-710 RZ, representative seed of which having been depositedunder NCIMB Accession No. 42336, wherein said plant may comprise atleast the following combination of traits including medium-late bolting,a semi-erect to horizontal plant habit, a smooth to semi-savoy leafsurface and resistance to downy mildew (P. farinosa f. sp. spinaciae)races Pfs1 to Pfs15.

In an embodiment of the present invention, there also is provided partsof a spinach plant of the invention, which may include parts of aspinach plant exhibiting a combination of traits including medium-latebolting, a semi-erect to horizontal plant habit, a smooth to semi-savoyleaf surface and resistance to downy mildew (P. farinosa f. sp.spinaciae) races Pfs1 to Pfs15, or parts of a spinach plant having anyof the aforementioned resistance(s) and a combination of traitsincluding one or more morphological or physiological characteristicstabulated herein, including parts of hybrid spinach variety 51-710 RZ,wherein the plant parts are involved in sexual reproduction, whichinclude without limitation, a microspore, pollen, an ovary, an ovule, anembryo sac or egg cell and/or wherein the plant parts are suitable forvegetative reproduction, which include, without limitation, a cutting, aroot, a stem, a cell or a protoplast and/or wherein the plant parts aretissue culture of regenerable cells in which the cells or protoplasts ofthe tissue culture are derived from a tissue such as, for example andwithout limitation, a leaf, pollen, an embryo, a cotyledon, a hypocotyl,a meristematic cell, a root, a root tip, an anther, a flower, a seed ora stem. The plants of the invention from which such parts can come frominclude those wherein representative seed of which has been depositedunder NCIMB Accession No. 42336 or hybrid spinach variety or cultivardesignated 51-710 RZ, as well as seed from such a plant, plant parts ofsuch a plant (such as those mentioned herein) and plants from such seedand/or progeny of such a plant, advantageously progeny exhibiting suchcombination of such traits, each of which, is within the scope of theinvention; and such combination of traits.

In another embodiment there is a plant grown from seeds, representativeseed of which having been deposited under NCIMB Accession No. 42336.

In a further embodiment there is a plant regenerated from theabove-described plant parts or regenerated from the above-describedtissue culture. Advantageously such a plant may have morphologicaland/or physiological characteristics of hybrid spinach variety 51-710 RZand/or of a plant grown from seed, representative seed of which havingbeen deposited under NCIMB Accession No. 42336—including withoutlimitation such plants having all of the morphological and physiologicalcharacteristics of hybrid spinach variety 51-710 RZ and/or of plantgrown from seed, representative seed of which having been depositedunder NCIMB Accession No. 42336. Advantageously, such a plantdemonstrates the traits of medium-late bolting, a semi-erect tohorizontal plant habit, a smooth to semi-savoy leaf surface andresistance to downy mildew (P. farinosa f. sp. spinaciae) races Pfs1 toPfs15.

Accordingly, in still a further embodiment, there is provided a spinachplant having all of the morphological and physiological characteristicsof hybrid spinach variety 51-710 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. 42336. Such a plant can begrown from the seeds, regenerated from the above-described plant parts,or regenerated from the above-described tissue culture. A spinach planthaving any of the aforementioned resistance(s), and one or moremorphological or physiological characteristics recited or tabulatedherein, and a spinach plant advantageously having all of theaforementioned resistances and the characteristics recited and tabulatedherein, are preferred. Parts of such plants—such as those plant partsabove-mentioned—are encompassed by the invention.

In an embodiment of the present invention, there is provided a spinachplant exhibiting a combination of traits which may comprise medium-latebolting, a semi-erect to horizontal plant habit, a smooth to semi-savoyleaf surface and resistance to downy mildew (P. farinosa f. sp.spinaciae) races Pfs1 to Pfs15, and having genetic material for soexhibiting the combination of traits; wherein the genetic information isas contained in a plant, representative seed of which having beendeposited under NCIMB Accession No. 42336. Parts of such plants—such asthose plant parts above-mentioned—are encompassed by the invention.

In one embodiment, there is provided a method for producing a progeny ofhybrid spinach variety 51-710 RZ which may comprise crossing the plantdesignated 51-710 RZ with itself or with another spinach plant,harvesting the resultant seed, and growing said seed.

In a further embodiment, there is provided progeny of spinach cultivar51-710 RZ produced by sexual or vegetative reproduction, grown fromseeds, regenerated from the above-described plant parts, or regeneratedfrom the above-described tissue culture of the spinach cultivar or aprogeny plant thereof, representative seed of which having beendeposited under NCIMB Accession No. 42336. The progeny may have any ofthe aforementioned resistance(s), and one or more morphological orphysiological characteristics recited or tabulated herein, and a progenyplant advantageously having all of the aforementioned resistances andthe characteristics recited and tabulated herein, is preferred.Advantageously, the progeny demonstrate the traits of medium-latebolting, a semi-erect to horizontal plant habit, a smooth to semi-savoyleaf surface and resistance to downy mildew (P. farinosa f. sp.spinaciae) races Pfs1 to Pfs15 and has genetic material for soexhibiting the combination of traits; wherein the genetic information isas contained in a plant, representative seed of which having beendeposited under NCIMB Accession No. 42336.

Progeny of the hybrid spinach variety 51-710 RZ may be modified in oneor more other characteristics, in which the modification is a result of,for example and without limitation, mutagenesis or transformation with atransgene.

In another embodiment the invention relates to a method of producing aninbred spinach plant derived from a plant of the invention of whichrepresentative seed has been deposited under NCIMB Accession No. 42336,which may comprise of the steps: a) preparing a progeny plant derivedfrom hybrid spinach variety 51-710 RZ by crossing a spinach plantexhibiting a combination of traits including medium-late bolting, asemi-erect to horizontal plant habit, a smooth to semi-savoy leafsurface and resistance to downy mildew (P. farinosa f. sp. spinaciae)races Pfs1 to Pfs15, representative seed of which have been depositedunder NCIMB Accession No. 42336 with itself or a second spinach plant;b) crossing the progeny plant with itself or a second spinach plant toproduce a seed of a progeny plant of a subsequent generation; c) growinga progeny plant of a subsequent generation from said seed and crossingthe progeny plant of a subsequent generation with itself or a secondspinach plant; and d) repeating step b) or c) for at least 3 moregenerations to produce an inbred spinach plant derived from the hybridspinach variety 51-710 RZ.

The invention even further relates to a method of producing spinachwhich may comprise: (a) cultivating to the vegetative plant stage aplant of hybrid spinach variety 51-710 RZ, representative seed of whichhaving been deposited under NCIMB Accession No. 42336, (b) harvestingspinach leaves from the plant, and (c) optionally using the harvestedspinach leaves as a fresh vegetable or (d) optionally using theharvested spinach leaves as a processed food. The harvested spinachleaves of step (c) or step (d) may optionally have undergone one or moreprocessing steps. Such a processing step might comprise but is notlimited to any one of the following treatments or combinations thereof:cutting, washing, blanching, cooking, steaming, baking, pasteurizing, orfreezing. The processed form that is obtained is also part of thisinvention. The invention further comprehends packaging the spinachleaves in fresh or processed form.

Accordingly, it is an object of the invention to not encompass withinthe invention any previously known product, process of making theproduct, or method of using the product such that Applicants reserve theright and hereby disclose a disclaimer of any previously known product,process, or method. It is further noted that the invention does notintend to encompass within the scope of the invention any product,process, or making of the product or method of using the product, whichdoes not meet the written description and enablement requirements of theUSPTO (35 U.S.C. §112, first paragraph) or the EPO (Article 83 of theEPC), such that Applicants reserve the right and hereby disclose adisclaimer of any previously described product, process of making theproduct, or method of using the product.

It is noted that in this disclosure and particularly in the claims,terms such as “comprises”, “comprised”, and “comprising” and the like(e.g., “includes”, “included”, “including”, “contains”, “contained”,“containing”, “has”, “had”, “having”, etc.) can have the meaningascribed to them in US patent law, i.e., they are open ended terms. Forexample, any method that “comprises,” “has” or “includes” one or moresteps is not limited to possessing only those one or more steps and alsocovers other unlisted steps. Similarly, any plant that “comprises,”“has” or “includes” one or more traits is not limited to possessing onlythose one or more traits and covers other unlisted traits. Similarly,the terms “consists essentially of” and “consisting essentially of” havethe meaning ascribed to them in US patent law, e.g., they allow forelements not explicitly recited, but exclude elements that are found inthe prior art or that affect a basic or novel characteristic of theinvention. See also MPEP §2111.03. In addition, the term “about” is usedto indicate that a value includes the standard deviation of error forthe device or method being employed to determine the value.

These and other embodiments are disclosed or are obvious from andencompassed by the following Detailed Description.

Deposit

The Deposit with NCIMB Ltd, Ferguson Building, Craibstone Estate,Bucksburn, Aberdeen AB21 9YA, UK, on Nov. 24, 2014, under depositaccession number NCIMB 42336 was made pursuant to the terms of theBudapest Treaty. Upon issuance of a patent, all restrictions upon thedeposit will be removed, and the deposit is intended to meet therequirements of 37 CFR §§1.801-1.809. The deposit will be irrevocablyand without restriction or condition released to the public upon theissuance of a patent. The deposit will be maintained in the depositoryfor a period of 30 years, or 5 years after the last request, or for theeffective life of the patent, whichever is longer, and will be replacedif necessary during that period.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawing, in which:

FIG. 1 is an illustration of the three different plant habits of plantsat prime market stage grown under optimal conditions.

FIG. 2 is an illustration of seven different leaf shapes from plants atprime market stage grown under optimal conditions.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides methods and compositions relating to plants,seeds and derivatives of a new hybrid spinach variety herein referred toas hybrid spinach variety 51-710 RZ. 51-710 RZ is a hybrid plant varietythat is uniform and distinct from other such hybrids, and can be stablyproduced after a cycle of reproduction.

There are numerous steps in the development of any novel, plant withdesirable characteristics. Selection of traits is a very importantaspect of plant breeding. Once desirable traits are identified, theplants with those desirable traits are crossed in order to recombine thedesirable traits and through selection, varieties or parent lines aredeveloped. The goal is to combine in a single variety or hybrid animproved combination of desirable traits from the parent plant. Theseimportant traits may include but are not limited to higher yield, fieldperformance, fruit and agronomic quality such as fruit shape, color andlength, resistance to diseases and insects, and tolerance to drought andheat.

Choice of breeding or selection methods depends on the mode of plantreproduction, the heritability of the trait(s) being improved, and thetype of cultivar used commercially (e.g., F1 hybrid cultivar, purelinecultivar, etc.). Popular selection methods commonly include but are notlimited to pedigree selection, modified pedigree selection, massselection, and recurrent selection.

The complexity of inheritance influences choice of the breeding method.Backcross breeding is used to transfer one or a few favorable genes fora highly heritable trait into a desirable cultivar. This approach isused extensively for breeding disease-resistant cultivars. Variousrecurrent selection techniques are used to improve quantitativelyinherited traits controlled by numerous genes. The use of recurrentselection in self-pollinating crops depends on the ease of pollination,the frequency of successful hybrids from each pollination, and thenumber of hybrid offspring from each successful cross.

The development of commercial spinach hybrids relates to the developmentof spinach parental lines, the crossing of these lines, and theevaluation of the crosses. Pedigree breeding and recurrent selectionbreeding methods are used to develop cultivars from breedingpopulations. Breeding programs combine desirable traits from two or morevarieties or various broad-based sources into breeding pools from whichlines are developed by selfing and selection of desired phenotypes. Thenew lines are crossed with other lines and the hybrids from thesecrosses are evaluated to determine which have the desirablecharacteristics.

Pedigree breeding is used commonly for the improvement ofself-pollinating crops or inbred lines of cross-pollinating crops. Twoparents which possess favorable, complementary traits are crossed toproduce an F1. An F2 population is produced by selfing one or severalF1s or by intercrossing two F1s (sib mating). Selection of the bestindividuals is usually begun in the F2 population; then, beginning inthe F3, the best individuals in the best families are selected.Replicated testing of families, or hybrid combinations involvingindividuals of these families, often follows in the F4 generation toimprove the effectiveness of selection for traits with low heritability.At an advanced stage of inbreeding (i.e., F6 and F7), the best lines ormixtures of phenotypically similar lines are tested for potentialrelease as new cultivars.

Mass and recurrent selections may be used to improve populations ofeither self- or cross-pollinating crops. A genetically variablepopulation of heterozygous individuals is either identified or createdby intercrossing several different parents. The best plants are selectedbased on individual superiority, outstanding progeny, or excellentcombining ability. The selected plants are intercrossed to produce a newpopulation in which further cycles of selection are continued.

Backcross breeding has been used to transfer genes for a simplyinherited, highly heritable trait into a desirable homozygous cultivaror line that is the recurrent parent. The source of the trait to betransferred is called the donor parent. The resulting plant is expectedto have the attributes of the recurrent parent (e.g., cultivar) and thedesirable trait transferred from the donor parent. After the initialcross, individuals possessing the phenotype of the donor parent areselected and repeatedly crossed (backcrossed) to the recurrent parent.The resulting plant is expected to have the attributes of the recurrentparent (e.g., cultivar) and the desirable trait transferred from thedonor parent.

Other methods of breeding may also relate to the single-seed descentprocedure which refers to planting a segregating population, harvestinga sample of one seed per plant, and using the one-seed sample to plantthe next generation. When the population has been advanced from the F2to the desired level of inbreeding, the plants from which lines arederived will each trace to different F2 individuals. The number ofplants in a population declines each generation due to failure of someseeds to germinate or some plants to produce at least one seed. As aresult, not all of the F2 plants originally sampled in the populationwill be represented by a progeny when generation advance is completed.

In addition to phenotypic observations, the genotype of a plant may alsobe examined. There are many laboratory-based techniques available forthe analysis, comparison and characterization of plant genotype; thesetechniques include but are not limited to Isozyme Electrophoresis,Restriction Fragment Length Polymorphisms (RFLPs), Randomly AmplifiedPolymorphic DNAs (RAPDs), Arbitrarily Primed Polymerase Chain Reaction(AP-PCR), DNA Amplification Fingerprinting (DAF), Sequence CharacterizedAmplified Regions (SCARs), Amplified Fragment Length polymorphisms(AFLPs), Simple Sequence Repeats (SSRs—which are also referred to asMicrosatellites), and Single Nucleotide Polymorphisms (SNPs)

Isozyme Electrophoresis and RFLPs have been widely used to determinegenetic composition. Shoemaker and Olsen, (Molecular Linkage Map ofSoybean (Glycine max) p 6.131-6.138 in S. J. O'Brien (ed) Genetic Maps:Locus Maps of Complex Genomes, Cold Spring Harbor Laboratory Press, ColdSpring Harbor, N.Y., (1993)) developed a molecular genetic linkage mapthat consisted of 25 linkage groups with about 365 RFLP, 11 RAPD, threeclassical markers and four isozyme loci. See also, Shoemaker, R. C.,RFLP Map of Soybean, p 299-309, in Phillips, R. L. and Vasil, I. K.,eds. DNA-Based Markers in Plants, Kluwer Academic Press, Dordrecht, theNetherlands (1994).

SSR technology is currently the most efficient and practical markertechnology; more marker loci may be routinely used and more alleles permarker locus may be found using SSRs in comparison to RFLPs. Forexample, Diwan and Cregan described a highly polymorphic microsatellitelocus in soybean with as many as 26 alleles. (Diwan, N. and Cregan, P.B., Theor. Appl. Genet. 95:22-225, 1997.) SNPs may also be used toidentify the unique genetic composition of the invention and progenyvarieties retaining that unique genetic composition. Various molecularmarker techniques may be used in combination to enhance overallresolution.

Molecular markers, which include markers identified through the use oftechniques such as Isozyme Electrophoresis, RFLPs, RAPDs, AP-PCR, DAF,SCARs, AFLPs, SSRs, and SNPs, may be used in plant breeding. One use ofmolecular markers is Quantitative Trait Loci (QTL) mapping. QTL mappingis the use of markers which are known to be closely linked to allelesthat have measurable effects on a quantitative trait. Selection in thebreeding process is based upon the accumulation of markers linked to thepositive effecting alleles and/or the elimination of the markers linkedto the negative effecting alleles from the plant's genome.

Molecular markers may also be used during the breeding process for theselection of qualitative traits. For example, markers closely linked toalleles or markers containing sequences within the actual alleles ofinterest may be used to select plants that contain the alleles ofinterest during a backcrossing breeding program. The markers may also beused to select toward the genome of the recurrent parent and against themarkers of the donor parent. This procedure attempts to minimize theamount of genome from the donor parent that remains in the selectedplants. It may also be used to reduce the number of crosses back to therecurrent parent needed in a backcrossing program. The use of molecularmarkers in the selection process is often called genetic marker enhancedselection or marker-assisted selection. Molecular markers may also beused to identify and exclude certain sources of germplasm as parentalvarieties or ancestors of a plant by providing a means of trackinggenetic profiles through crosses.

Mutation breeding is another method of introducing new traits intospinach varieties. Mutations that occur spontaneously or areartificially induced may be useful sources of variability for a plantbreeder. The goal of artificial mutagenesis is to increase the rate ofmutation for a desired characteristic. Mutation rates may be increasedby many different means including temperature, long-term seed storage,tissue culture conditions, radiation (such as X-rays, Gamma rays,neutrons, Beta radiation, or ultraviolet radiation), chemical mutagens(such as base analogs like 5-bromo-uracil), antibiotics, alkylatingagents (such as sulfur mustards, nitrogen mustards, epoxides,ethyleneamines, sulfates, sulfonates, sulfones, or lactones), azide,hydroxylamine, nitrous acid or acridines. Once a desired trait isobserved through mutagenesis the trait may then be incorporated intoexisting germplasm by traditional breeding techniques. Details ofmutation breeding may be found in Principles of Cultivar Development byFehr, Macmillan Publishing Company, 1993.

The production of double haploids may also be used for the developmentof homozygous lines in a breeding program. Double haploids are producedby the doubling of a set of chromosomes from a heterozygous plant toproduce a completely homozygous individual. For example, see Wan et al.,Theor. Appl. Genet., 77:889-892, 1989.

The spinach plant of the invention may be arrived at through crossing ofinbred lines or through selection of the disclosed desirablecharacteristics by any of the breeding the selection methods mentionedabove.

The parents of hybrid spinach variety 51-710 RZ were developed asfollows: The mother is a spinach line made from pedigree selection fromno. 09.79119. In total four selection, crossing and selfing cycles andone round of mass generation and selection was performed. The fatherline of 51-710 RZ is made from pedigree selection from no. 05.89062,obtained by three selection and inbreeding cycles, and one round of massgeneration and selection. Crossing the described mother and fatherinbred spinach lines with one another will yield uniform F1 hybridprogeny plants. Table 1 shows the pedigree scheme of the mother line,Table 2 shows the pedigree scheme of the father line of hybrid spinachline 51-710 RZ.

TABLE 1 Breeding history of the mother line of 51-710 RZ. Year Year 1 F1pedigree selection from 09.79119 Year 2 S1 F1 generation grown Year 3 S2F1 generation grown Year 4 S3 F1 generation grown Year 5 M1 S3 F1generation grown (in mass)

TABLE 2 Breeding history of the father line of 51-710 RZ. Year Year 1 F1pedigree selection from 05.89062 Year 1 S1 F1 generation grown Year 2 S2F1 generation grown Year 3 S3 F1 generation grown Year 6 M1 S3 F1generation grown (in mass)

In one embodiment, a plant of the invention has all the morphologicaland physiological characteristics of spinach variety 51-710 RZ. Thesecharacteristics of a spinach plant of the invention, e.g. variety 51-710RZ, are summarized and compared to its closest publicly availablevariety in Table 3.

The information presented in Table 3 was determined in trial experimentsin accordance with the Exhibit C Form provided by the United StatesDepartment of Agriculture Plant Variety Protection Office. Theterminology used in these tables is the official terminology found inthe Exhibit C Form as of the filing date, and is thus clear for a personskilled in the art.

TABLE 3 Physiological and morphological characteristics of 51-710 RZ incomparison with closest known variety “Crocodile”. Character 51-710 RZCrocodile RZ Ploidy Diploid Diploid Plant (Prime market stage): HabitSemi-erect Semi-erect Size Medium Medium Spread (cm) 38 35 Height (cm)18 16 Seedling cotyledon Width (mm) 5 6 Length (mm) 55 56 Tip Roundpointed Round Pointed Color chart RHS 137C RHS 137C Leaf (First foliageleaves) Shape Ovate Ovate Base Lobed Lobed Tip Round pointed Roundpointed Margin Flat Curled under Upper surface color chart RHS 137B RHS137A Lower surface color chart RHS 137BC RHS 137B Leaf (Prime marketstage) Surface Smooth to semi-savoy Semi savoy Shape Ovate Ovate BaseLobed Lobed Tip Round Round Margin Flat Flat Upper surface color chartRHS 137A RHS 137B Lower surface color chart RHS 137C RHS 137D LusterGlossy Glossy Blade size Small Small Blade lobing Not lobed Not lobedPetiole color Light green Light green Color chart RHS 137B RHS 137BPetiole red pigmentation Absent Absent Petiole length to blade (cm) 5.45.6 Petiole diameter (mm) 4 5

Aside from the morphological and physiological characteristics mentionedin Table 3, a plant of the invention also exhibits resistance to downymildew (Peronospora farinosa f. sp. Spinaciae).

As used herein, resistance to Peronospora farinosa f. sp. Spinaciae isdefined as the ability of a plant to resist infection by each of thevarious races Pfs1-Pfs15 in all stages between the seedling stage andthe harvestable prime market stage.

The resistance to downy mildew infection was assayed as described byIrish et al. (2008; Phytopathol. 98: 894-900; incorporated herein byreference), using a differential set. Resistance is tested byinoculating plants at the true leaf stage, and observing symptoms ofchlorosis and sporulation 7 days later.

As used herein, the leaf surface is by visual comparison to standardvarieties at prime market stage. Three different leaf surface types arerecognised: smooth, semi-savoy, or savoy. Leaf surface is determined bycomparison to standard varieties Viroflay, Northland, and VirginiaSavoy. Viroflay has smooth leaves, Northland has semi-savoy leaves,while Virginia Savoy has savoy leaves. The leaf surface of hybridspinach variety 51-710 RZ is smooth to semi-savoy which is in betweenthe leaf surfaces of varieties Viroflay and Northland but more similarto Northland, and is at prime market stage more smooth than the leavesof variety Crocodile RZ.

As used herein, plant habit is by visual comparison to standardvarieties. Plant habit terminology is in concordance with the petioleattitude terminology used on the UPOV TG/55/7 Form. On the UPOV TG/55/7Petiole attitudes are determined by comparison to standard varietiesGrappa, Monnopa, Parrot, Comte and Lavewa. Grappa is a variety with anerect petiole attitude; Monnopa and Parrot are varieties with asemi-erect petiole attitude; Comte and Lavewa are varieties with ahorizontal petiole attitude. Plants of hybrid variety 51-710 RZ have apetiole attitude that is in between the petiole attitudes of semi-erectvarieties Monnopa and Parrot and horizontal varieties Lavewa and Mystic,and hybrid variety 51-710 RZ is thus considered to have a semi-erect tohorizontal petiole attitude. The plant habit of variety 51-710 RZ issemi-erect when using plant habit terminology in concordance with thatused on the Exhibit C Form provided by the United States Department ofAgriculture Plant Variety Protection Office. On the Exhibit C Form threedifferent habits are recognized, and are shown in FIG. 1. “Flat”, whichis comparable to the habit of plants of variety Viroflay; “semi-erect”,which is comparable to the habit of plants of variety Long StandingBloomsdale; and “erect”, which is comparable to the habit of plants ofvariety Virginia Savoy. Plants of hybrid variety 51-710 RZ have asemi-erect plant habit, which is thus comparable to that of plants ofvariety Long Standing Bloomsdale.

As used herein, bolting is defined in concordance with the definition onthe UPOV TG/55/7 Form as the time it requires for 15% of the plants tobegin to have a central flowering stem appear through the stretching ofthe internodes for spring sown crops. Bolting is determined bycomparison to standard varieties Figo, Maracas, Bandola, Viroflay,Matador, Monnopa, Grappa, Medania, Revolver, Chica and Lavewa. Figo andMaracas are very early bolting varieties; Bandola and Viroflay are earlybolting varieties; Matador and Monnopa are medium bolting varieties;Grappa, Medania and Revolver are late bolting varieties and Chica andLavewa are very late bolting varieties. Hybrid spinach variety 51-710 RZhas a timing of bolting that is in between that of medium boltingvarieties Matador and Monnopa and late bolting varieties Grappa, Medaniaand Revolver, and is therefore considered a medium-late bolting variety.

As used herein, the leaf shape terminology is in concordance with thatused on the UPOV TG/55/7 Form. Hybrid spinach variety 51-710 RZ hasmedium ovate mature leaves. The leaves of hybrid spinach variety 51-710RZ are medium ovate as they are similar in shape to those of varietiesLavewa and Resistoflay, which are the standard comparison varieties forassessing the shape of the leaf blade on the UPOV TG/55/7 Form with amedium ovate leaf shape. The leaves are ovate as defined on the ExhibitC Form provided by the United States Department of Agriculture PlantVariety Protection Office and shown in FIG. 2.

Embodiments of the invention advantageously have one or more, and mostadvantageously all, of these characteristics.

In an embodiment, the invention relates to spinach plants that have allthe morphological and physiological characteristics of the invention andhave acquired said characteristics by introduction of the geneticinformation that is responsible for the characteristics from a suitablesource, either by conventional breeding, or genetic modification, inparticular by cisgenesis or transgenesis. Cisgenesis is geneticmodification of plants with a natural gene, coding for an (agricultural)trait, from the crop plant itself or from a sexually compatible donorplant. Transgenesis is genetic modification of a plant with a gene froma non-crossable species or a synthetic gene.

Just as useful traits that may be introduced into a hybrid bybackcrossing the trait into one or both parents, useful traits may beintroduced directly into the plant of the invention, being a plant ofhybrid spinach variety 51-710 RZ, by genetic transformation techniques;and, such plants of hybrid spinach variety 51-710 RZ that haveadditional genetic information introduced into the genome or thatexpress additional traits by having the DNA coding there for introducedinto the genome via transformation techniques, are within the ambit ofthe invention, as well as uses of such plants, and the making of suchplants.

Genetic transformation may therefore be used to insert a selectedtransgene into the plant of the invention, being a plant of hybridspinach variety 51-710 RZ or may, alternatively, be used for thepreparation of transgenes which may be introduced by backcrossing.Methods for the transformation of plants, including spinach, are wellknown to those of skill in the art.

Vectors used for the transformation of spinach cells are not limited solong as the vector may express an inserted DNA in the cells. Forexample, vectors which may comprise promoters for constitutive geneexpression in spinach cells (e.g., cauliflower mosaic virus 35Spromoter) and promoters inducible by exogenous stimuli may be used.Examples of suitable vectors include pBI binary vector. The “spinachcell” into which the vector is to be introduced includes various formsof spinach cells, such as cultured cell suspensions, protoplasts, leafsections, and callus. A vector may be introduced into spinach cells byknown methods, such as the polyethylene glycol method, polycationmethod, electroporation, Agrobacterium-mediated transfer, particlebombardment and direct DNA uptake by protoplasts. To effecttransformation by electroporation, one may employ either friabletissues, such as a suspension culture of cells or embryogenic callus oralternatively one may transform immature embryos or other organizedtissue directly. In this technique, one would partially degrade the cellwalls of the chosen cells by exposing them to pectin-degrading enzymes(pectolyases) or mechanically wound tissues in a controlled manner.

A particularly efficient method for delivering transforming DNA segmentsto plant cells is microprojectile bombardment. In this method, particlesare coated with nucleic acids and delivered into cells by a propellingforce. Exemplary particles include those which may be comprised oftungsten, platinum, and preferably, gold. For the bombardment, cells insuspension are concentrated on filters or solid culture medium.Alternatively, immature embryos or other target cells may be arranged onsolid culture medium. The cells to be bombarded are positioned at anappropriate distance below the macroprojectile stopping plate. Anillustrative embodiment of a method for delivering DNA into plant cellsby acceleration is the Biolistics Particle Delivery System, which may beused to propel particles coated with DNA or cells through a screen, suchas a stainless steel or Nytex screen, onto a surface covered with targetspinach cells. The screen disperses the particles so that they are notdelivered to the recipient cells in large aggregates. It is believedthat a screen intervening between the projectile apparatus and the cellsto be bombarded reduces the size of projectiles aggregate and maycontribute to a higher frequency of transformation by reducing thedamage inflicted on the recipient cells by projectiles that are toolarge. Microprojectile bombardment techniques are widely applicable, andmay be used to transform virtually any plant species, including a plantof spinach variety 51-710 RZ.

Agrobacterium-mediated transfer is another widely applicable system forintroducing gene loci into plant cells. An advantage of the technique isthat DNA may be introduced into whole plant tissues, thereby bypassingthe need for regeneration of an intact plant from a protoplast.Agrobacterium transformation vectors are capable of replication in E.coli as well as Agrobacterium, allowing for convenient manipulations.Moreover, advances in vectors for Agrobacterium-mediated gene transferhave improved the arrangement of genes and restriction sites in thevectors to facilitate the construction of vectors capable of expressingvarious polypeptide coding genes. The vectors have convenientmulti-linker regions flanked by a promoter and a polyadenylation sitefor direct expression of inserted polypeptide coding genes.Additionally, Agrobacterium containing both armed and disarmed Ti genesmay be used for transformation. In those plant strains whereAgrobacterium-mediated transformation is efficient, it is the method ofchoice because of the facile and defined nature of the gene locustransfer. The use of Agrobacterium-mediated plant integrating vectors tointroduce DNA into plant cells, including spinach plant cells, is wellknown in the art (See, e.g., U.S. Pat. Nos. 7,250,560 and 5,563,055).

Transformation of plant protoplasts also may be achieved using methodsbased on calcium phosphate precipitation, polyethylene glycol treatment,electroporation, and combinations of these treatments.

A number of promoters have utility for plant gene expression for anygene of interest including but not limited to selectable markers,scoreable markers, genes for pest tolerance, disease resistance,nutritional enhancements and any other gene of agronomic interest.Examples of constitutive promoters useful for spinach plant geneexpression include, but are not limited to, the cauliflower mosaic virus(CaMV) P-35S promoter, a tandemly duplicated version of the CaMV 35Spromoter, the enhanced 35S promoter (P-e35S), the nopaline synthasepromoter, the octopine synthase promoter, the figwort mosaic virus(P-FMV) promoter (see U.S. Pat. No. 5,378,619), an enhanced version ofthe FMV promoter (P-eFMV) where the promoter sequence of P-FMV isduplicated in tandem, the cauliflower mosaic virus 19S promoter, asugarcane bacilliform virus promoter, a commelina yellow mottle viruspromoter, the promoter for the thylakoid membrane proteins from spinach(psaD, psaF, psaE, PC, FNR, atpC, atpD, cab, rbcS) (see U.S. Pat. No.7,161,061), the CAB-1 promoter from spinach (see U.S. Pat. No.7,663,027), the promoter from maize prolamin seed storage protein (seeU.S. Pat. No. 7,119,255), and other plant DNA virus promoters known toexpress in plant cells. A variety of plant gene promoters that areregulated in response to environmental, hormonal, chemical, and/ordevelopmental signals may be used for expression of an operably linkedgene in plant cells, including promoters regulated by (1) heat, (2)light (e.g., pea rbcS-3A promoter, maize rbcS promoter, or chlorophylla/b-binding protein promoter), (3) hormones, such as abscisic acid, (4)wounding (e.g., wunl, or (5) chemicals such as methyl jasmonate,salicylic acid, or Safener. It may also be advantageous to employorgan-specific promoters.

Exemplary nucleic acids which may be introduced to the spinach varietyof this invention include, for example, DNA sequences or genes fromanother species, or even genes or sequences which originate with or arepresent in spinach species, but are incorporated into recipient cells bygenetic engineering methods rather than classical reproduction orbreeding techniques. However, the term “exogenous” is also intended torefer to genes that are not normally present in the cell beingtransformed, or perhaps simply not present in the form, structure, etc.,as found in the transforming DNA segment or gene, or genes which arenormally present and that one desires to express in a manner thatdiffers from the natural expression pattern, e.g., to over-express.Thus, the term “exogenous” gene or DNA is intended to refer to any geneor DNA segment that is introduced into a recipient cell, regardless ofwhether a similar gene may already be present in such a cell. The typeof DNA included in the exogenous DNA may include DNA which is alreadypresent in the plant cell, DNA from another plant, DNA from a differentorganism, or a DNA generated externally, such as a DNA sequencecontaining an antisense message of a gene, or a DNA sequence encoding asynthetic or modified version of a gene.

Many hundreds if not thousands of different genes are known and couldpotentially be introduced into a plant of spinach variety 51-710 RZ.Non-limiting examples of particular genes and corresponding phenotypesone may choose to introduce into a spinach plant include one or moregenes for insect tolerance, pest tolerance such as genes for fungaldisease control, herbicide tolerance, and genes for quality improvementssuch as yield, nutritional enhancements, environmental or stresstolerances, or any desirable changes in plant physiology, growth,development, morphology or plant product(s).

Alternatively, the DNA coding sequences may affect these phenotypes byencoding a non-translatable RNA molecule that causes the targetedinhibition of expression of an endogenous gene, for example viaantisense- or cosuppression-mediated mechanisms. The RNA could also be acatalytic RNA molecule (i.e., a ribozyme) engineered to cleave a desiredendogenous mRNA product. Thus, any gene which produces a protein or mRNAwhich expresses a phenotype or morphology change of interest is usefulfor the practice of the present invention. (See also U.S. Pat. No.7,576,262, “Modified gene-silencing RNA and uses thereof.”)

U.S. Pat. Nos. 7,230,158, 7,122,720, 7,081,363, 6,734,341, 6,503,732,6,392,121, 6,087,560, 5,981,181, 5,977,060, 5,608,146, 5,516,667, eachof which, and all documents cited therein are hereby incorporated hereinby reference, consistent with the above INCORPORATION BY REFERENCEsection, are additionally cited as examples of U.S. patents that mayconcern transformed spinach and/or methods of transforming spinach orspinach plant cells, and techniques from these US patents, as well aspromoters, vectors, etc., may be employed in the practice of thisinvention to introduce exogenous nucleic acid sequence(s) into a plantof spinach variety 51-710 RZ (or cells thereof), and exemplify someexogenous nucleic acid sequence(s) which may be introduced into a plantof spinach variety 51-710 RZ (or cells thereof) of the invention, aswell as techniques, promoters, vectors etc., to thereby obtain furtherplants of spinach variety 51-710 RZ, plant parts and cells, seeds, otherpropagation material harvestable parts of these plants, etc. of theinvention, e.g. tissue culture, including a cell or protoplast, such asan embryo, meristem, cotyledon, pollen, leaf, anther, root, root tip,pistil, flower, seed or stalk.

The invention further relates to propagation material for producingplants of the invention. Such propagation material may comprise interalia seeds of the claimed plant and parts of the plant that are involvedin sexual reproduction. Such parts are for example selected from thegroup consisting of seeds, microspores, pollen, ovaries, ovules, embryosacs and egg cells. In addition, the invention relates to propagationmaterial which may comprise parts of the plant that are suitable forvegetative reproduction, for example cuttings, roots, stems, cells,protoplasts.

According to a further aspect thereof the propagation material of theinvention may comprise a tissue culture of the claimed plant. The tissueculture may comprise regenerable cells. Such tissue culture may bederived from leaves, pollen, embryos, cotyledon, hypocotyls,meristematic cells, roots, root tips, anthers, flowers, seeds and stems(See generally U.S. Pat. No. 7,041,876 on spinach being recognized as aplant that may be regenerated from cultured cells or tissue).

Also, the invention comprehends methods for producing a seed of a“51-710 RZ”-derived spinach plant which may comprise (a) crossing aplant of spinach variety 51-710 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. 42336, with a second spinachplant, and (b) whereby seed of a “51-710 RZ”-derived spinach plantforms. Such a method may further comprise (c) crossing a plant grownfrom “51-710 RZ”-derived spinach seed with itself or with a secondspinach plant to yield additional “51-710 RZ”-derived spinach seed, (d)growing the additional “51-710 RZ”-derived spinach seed of step (c) toyield additional “51-710 RZ”-derived spinach plants, and (e) repeatingthe crossing and growing of steps (c) and (d) for an additional 3-10generations to further generate “51-710 RZ”-derived spinach plants.

The invention further relates to the above methods that may furthercomprise selecting at steps b), d), and e), a “51-710 RZ”-derivedspinach plant exhibiting a combination of traits including medium-latebolting, a semi-erect to horizontal plant habit, a smooth to semi-savoyleaf surface and resistance to downy mildew (P. farinosa f. sp.spinaciae) races Pfs1 to Pfs15.

In particular, the invention relates to methods for producing a seed ofa “51-710 RZ”-derived spinach plant which may comprise (a) crossing aplant of spinach variety 51-710 RZ, representative seed of which havingbeen deposited under NCIMB Accession No. 42336, with a second spinachplant and (b) whereby seed of a 51-710 RZ-derived spinach plant forms,wherein such a method may further comprise (c) crossing a plant grownfrom 51-710 RZ-derived spinach seed with itself or with a second spinachplant to yield additional 51-710 RZ-derived spinach seed, (d) growingthe additional 51-710 RZ-derived spinach seed of step (c) to yieldadditional 51-710 RZ-derived spinach plants and selecting plantsexhibiting a combination of the traits including medium-late bolting, asemi-erect to horizontal plant habit, a smooth to semi-savoy leafsurface and resistance to downy mildew (P. farinosa f. sp. spinaciae)races Pfs1 to Pfs15, and (e) repeating the crossing and growing of steps(c) and (d) for an additional 3-10 generations to further generate51-710 RZ-derived spinach plants that exhibit a combination of traitsmedium-late bolting, a semi-erect to horizontal plant habit, a smooth tosemi-savoy leaf surface and resistance to downy mildew (P. farinosa f.sp. spinaciae) races Pfs1 to Pfs15.

Backcrossing one of the parents of a hybrid may also be used to improvean inbred plant. Backcrossing transfers a specific desirable trait fromone inbred or non-inbred source to an inbred that lacks that trait. Thismay be accomplished, for example, by first crossing a superior inbred(A) (recurrent parent) to a donor inbred (non-recurrent parent), whichcarries the appropriate locus or loci for the trait in question. Theprogeny of this cross are then mated back to the superior recurrentparent (A) followed by selection in the resultant progeny for thedesired trait to be transferred from the non-recurrent parent. Afterfive or more backcross generations with selection for the desired trait,the progeny are heterozygous for loci controlling the characteristicbeing transferred, but are like the superior parent for most or almostall other loci. The last backcross generation would be selfed to givepure breeding progeny for the trait being transferred.

The invention additionally provides a method of introducing a desiredtrait into a plant of hybrid spinach variety 51-710 RZ by reversebreeding (See generally U.S. application Ser. No. 10/487,468, publishedas 2006-0179498 A1), which may comprise the following steps: (a)allowing the hybrid spinach plant to produce haploid cells, whilesuppressing recombination, (b) growing haploid plants into diploidplants, (c) selecting those homozygous plants which together constitutethe hybrid variety of the invention as parent plants for the saidhybrid, (d) crossing one of the said parent plants with a plant whichmay have the desired trait, (e) crossing the selected F1 progeny withsaid parent plant, to produce backcross progeny; (f) selecting backcrossprogeny which may comprise the desired trait and the physiological andmorphological characteristic of the parent plant; and, optionally, (g)repeating steps (e) and (f) one or more times in succession to produceselected fourth or higher backcross progeny that may comprise thedesired trait and all of the physiological and morphologicalcharacteristics of said parent plant, (h) crossing the backcrossedparent plant having the added desired trait with the other parent plantobtained after reverse breeding to obtain a plant which may comprise thedesired trait and all of the physiological and morphologicalcharacteristics of a plant of spinach variety 51-710 RZ.

The invention further involves a method of determining the genotype of aplant of spinach variety 51-710 RZ, representative seed of which hasbeen deposited under NCIMB Accession No. 42336, or a first generationprogeny thereof, which may comprise obtaining a sample of nucleic acidsfrom said plant and detecting in said nucleic acids a plurality ofpolymorphisms. This method may additionally comprise the step of storingthe results of detecting the plurality of polymorphisms on a computerreadable medium. The plurality of polymorphisms are indicative of and/orgive rise to the expression of the morphological and physiologicalcharacteristics of spinach variety 51-710 RZ.

There are various ways of obtaining genotype data from a nucleic acidsample. Genotype data may be gathered which is specific for certainphenotypic traits (e.g. gene sequences), but also patterns of randomgenetic variation may be obtained to construct a so-called DNAfingerprint. Depending on the technique used a fingerprint may beobtained that is unique for hybrid spinach variety 51-710 RZ. Obtaininga unique DNA fingerprint depends on the genetic variation present in avariety and the sensitivity of the fingerprinting technique. A techniqueknown in the art to provide a good fingerprint profile is called theAFLP fingerprinting technique (See generally U.S. Pat. No. 5,874,215),but there are many other marker-based techniques, such as RFLP (orRestriction fragment length polymorphism), SSLP (or Simple sequencelength polymorphism), RAPD (or Random amplification of polymorphic DNA),VNTR (or Variable number tandem repeat), Microsatellite polymorphism,SSR (or Simple sequence repeat), STR (or Short tandem repeat), SFP (orSingle feature polymorphism), DArT (or Diversity Arrays Technology), RADmarkers (or Restriction site associated DNA markers) (e.g. Semagn et al.African Journal of Biotechnology Vol. 5 number 25 pp. 2540-2568, 29Dec., 2006; Baird et al. PloS ONE Vol. 3 number 10 e3376, 2008).Nowadays, sequence-based methods are utilising Single NucleotidePolymorphisms (SNPs) that are randomly distributed across genomes, as acommon tool for genotyping (eg. Elshire et al. PloS ONE Vol. 6 number 5e19379, 2011; Poland et al. PloS ONE Vol. 7 number 2 e32253, 2012;Truong et al. PloS ONE Vol. 7 number 5 e37565, 2012).

With any of the aforementioned genotyping techniques, polymorphisms maybe detected when the genotype and/or sequence of the plant of interestis compared to the genotype and/or sequence of one or more referenceplants. As used herein, the genotype and/or sequence of a referenceplant may be derived from, but is not limited to, any one of thefollowing: parental lines, closely related plant varieties or species,complete genome sequence of a related plant variety or species, or thede novo assembled genome sequence of one or more related plant varietiesor species. It is possible, for example, to detect polymorphisms for thecharacteristic of the resistance to downy mildew (Peronospora farinosaf. sp. spinaciae) races Pfs1 to Pfs15 by comparing the genotype and/orthe sequence of spinach variety 51-710 RZ with the genotype and/or thesequence of one or more reference plants. The reference plant(s) usedfor comparison may for example be, but is not limited to, the comparisonvariety Crocodile or a variety included in Table 4 of this application.

The polymorphisms revealed by these techniques may be used to establishlinks between genotype and phenotype. The polymorphisms may thus be usedto predict or identify certain phenotypic characteristics, individuals,or even species. The polymorphisms are generally called markers. It iscommon practice for the skilled artisan to apply molecular DNAtechniques for generating polymorphisms and creating markers.

The polymorphisms of this invention may be provided in a variety ofmediums to facilitate use, e.g. a database or computer readable medium,which may also contain descriptive annotations in a form that allows askilled artisan to examine or query the polymorphisms and obtain usefulinformation.

As used herein “database” refers to any representation of retrievablecollected data including computer files such as text files, databasefiles, spreadsheet files and image files, printed tabulations andgraphical representations and combinations of digital and image datacollections. In a preferred aspect of the invention, “database” refersto a memory system that may store computer searchable information.

As used herein, “computer readable media” refers to any medium that maybe read and accessed directly by a computer. Such media include, but arenot limited to: magnetic storage media, such as floppy discs, hard disc,storage medium and magnetic tape; optical storage media such as CD-ROM;electrical storage media such as RAM, DRAM, SRAM, SDRAM, ROM; and PROMs(EPROM, EEPROM, Flash EPROM), and hybrids of these categories such asmagnetic/optical storage media. A skilled artisan may readily appreciatehow any of the presently known computer readable mediums may be used tocreate a manufacture which may comprise computer readable medium havingrecorded thereon a polymorphism of the present invention.

As used herein, “recorded” refers to the result of a process for storinginformation in a retrievable database or computer readable medium. Forinstance, a skilled artisan may readily adopt any of the presently knownmethods for recording information on computer readable medium togenerate media which may comprise the polymorphisms of the presentinvention. A variety of data storage structures are available to askilled artisan for creating a computer readable medium where the choiceof the data storage structure will generally be based on the meanschosen to access the stored information. In addition, a variety of dataprocessor programs and formats may be used to store the polymorphisms ofthe present invention on computer readable medium.

The present invention further provides systems, particularlycomputer-based systems, which contain the polymorphisms describedherein. Such systems are designed to identify the polymorphisms of thisinvention. As used herein, “a computer-based system” refers to thehardware, software and memory used to analyze the polymorphisms. Askilled artisan may readily appreciate that any one of the currentlyavailable computer-based system are suitable for use in the presentinvention.

Spinach leaves are sold in packaged form, including without limitationas pre-packaged spinach salad or as canned spinach or as frozen spinach.Mention is made of U.S. Pat. No. 5,523,136, incorporated herein byreference consistent with the above INCORPORATION BY REFERENCE section,which provides packaging film, and packages from such packaging film,including such packaging containing leafy produce, and methods formaking and using such packaging film and packages, which are suitablefor use with the spinach leaves of the invention. Thus, the inventioncomprehends the use of and methods for making and using the leaves ofthe spinach of the invention, as well as leaves of spinach derived fromthe invention.

The invention further relates to a container which may comprise one ormore plants of the invention, or one or more spinach plants derived froma plant of the invention, in a growth substrate for harvest of leavesfrom the plant in a domestic environment. This way the consumer may pickvery fresh leaves for use in salads. More generally, the inventionincludes one or more plants of the invention or one or more plantsderived from spinach of the invention, wherein the plant is in aready-to-harvest condition, including with the consumer picking his own,and further including a container which may comprise one or more ofthese plants.

The invention is further described by the following numbered paragraphs:

1. A spinach plant designated 51-710 RZ, representative seed of whichhaving been deposited under NCIMB Accession No. 42336, wherein saidplant comprises at least the following combination of traits includingmedium-late bolting, a semi-erect to horizontal plant habit, a smooth tosemi-savoy leaf surface and resistance to downy mildew (P. farinosa f.sp. spinaciae) races Pfs1 to Pfs15.

2. The spinach plant of paragraph 1 wherein said combination of traitsfurther comprises medium ovate mature leaves.

3. A seed of the plant of paragraph 1.

4. A part of the plant of paragraph 1, wherein said part of the plant issuitable for sexual reproduction.

5. A part of the plant as described in paragraph 4, wherein said partcomprises a microspore, pollen, an ovary, an ovule, an embryo sac or anegg cell.

6. A part of the plant of paragraph 1, wherein said part of the plant issuitable for vegetative reproduction.

7. A part of the plant as described in paragraph 6, wherein said partcomprises a cutting, a root, a stem, a cell or a protoplast.

8. A tissue culture of regenerable cells from the spinach plant ofparagraph 1.

9. The cell or protoplast of paragraph 7 derived from a leaf, pollen, anembryo, a cotyledon, a hypocotyl, a meristematic cell, a root, a roottip, an anther, a flower, a seed or a stem.

10. A spinach plant exhibiting a combination of traits comprisingmedium-late bolting, a semi-erect to horizontal plant habit, a smooth tosemi-savoy leaf surface and resistance to downy mildew (P. farinosa f.sp. spinaciae) races Pfs1 to Pfs15, and having genetic material for soexhibiting the combination of traits; wherein the genetic information isas contained in a plant, representative seed of which having beendeposited under NCIMB Accession No. 42336.

11. Progeny plant of the plant of claim 10, wherein said progeny plantis produced by sexual or vegetative reproduction of said spinach plant,and wherein said progeny plant has genetic material for exhibiting acombination of traits comprising medium-late bolting, a semi-erect tohorizontal plant habit, a smooth to semi-savoy leaf surface andresistance to downy mildew (P. farinosa f. sp. spinaciae) races Pfs1 toPfs15; wherein the genetic information is as contained in a plant,representative seed of which having been deposited under NCIMB AccessionNo. 42336.

12. A method for producing a progeny plant of the spinach plant ofparagraph 1, comprising crossing the plant of paragraph 1 with itself orwith another spinach plant, harvesting the resultant seed, and growingsaid seed into a progeny plant.

13. A progeny plant produced by the method of paragraph 12, wherein saidprogeny plant has genetic material for exhibiting a combination oftraits comprising medium-late bolting, a semi-erect to horizontal planthabit, a smooth to semi-savoy leaf surface and resistance to downymildew (P. farinosa f. sp. spinaciae) races Pfs1 to Pfs15; wherein thegenetic information is as contained in a plant, representative seed ofwhich having been deposited under NCIMB Accession No. 42336.

14. A progeny plant of the spinach plant of paragraph 1, having all themorphological and physiological characteristics of the spinach plant ofparagraph 1, representative seed of which having been deposited underNCIMB Accession No. 42336, wherein the morphological and physiologicalcharacteristics are as found in spinach variety 51-710 RZ,representative seed of which having been deposited under NCIMB AccessionNo. 42336.

15. A progeny plant of the spinach plant as defined in paragraph 1,representative seed of which having been deposited under NCIMB AccessionNo. 42336, wherein the progeny plant exhibits the combination of traitsof the spinach plant of paragraph 1 and has genetic material for soexhibiting the combination of traits; wherein the genetic information isas contained in a plant, representative seed of which having beendeposited under NCIMB Accession No. 42336 and is further modified in oneor more other characteristics.

16. The progeny plant as defined in paragraph 15, wherein themodification is effected by mutagenesis.

17. The progeny plant as defined in paragraph 15, wherein themodification is effected by transformation with a transgene.

18. A method of producing an inbred spinach plant derived from hybridspinach variety 51-710 RZ, comprising the steps:

a) preparing a progeny plant derived from hybrid spinach variety 51-710RZ by crossing the plant of paragraph 1 with itself or a second spinachplant;

b) crossing the progeny plant with itself or a second spinach plant toproduce a seed of a progeny plant of a subsequent generation;

c) growing a progeny plant of a subsequent generation from said seed andcrossing the progeny plant of a subsequent generation with itself or asecond spinach plant; and

d) repeating step b) and c) for at least 3 more generations to producean inbred spinach plant derived from the hybrid spinach variety 51-710RZ.

19. An inbred spinach plant produced by the method of paragraph 18.

20. A method for producing spinach leaves comprising: a) obtaining aplant according to paragraph 1, wherein the plant has been cultivated toobtain leaves; and b) harvesting the spinach leaves from the plant.

21. A method for producing spinach leaves as a fresh vegetablecomprising packaging the leaves of the plant of paragraph 1.

22. A method for producing spinach leaves as a processed food comprisingprocessing the leaves of the plant of paragraph 1.

23. One or more spinach plants of paragraph 1, in a container, for theharvest of leaves.

24. A spinach plant having all morphological and physiologicalcharacteristics of a spinach plant, representative seed of which havingbeen deposited under NCIMB Accession No. 42336.

25. A method for producing a seed of a hybrid spinach variety 51-710RZ-derived spinach plant comprising the steps of (a) crossing a spinachplant of hybrid spinach variety 51-710 RZ, representative seed of whichhaving been deposited under NCIMB Accession No. 42336, with a secondspinach plant or itself, and (b) allowing seed of a 51-710 RZ-derivedspinach plant to form.

26. The method of paragraph 25 further comprising the steps of (c)selfing a plant grown from said 51-710 RZ-derived spinach seed orcrossing it to a second spinach plant to yield additional 51-710RZ-derived spinach seed, (d) growing the said additional 51-710RZ-derived spinach seed of step (c) to yield additional 51-710RZ-derived spinach plants, and (e) repeating the crossing and growing ofsteps (c) and (d) for an additional 3-10 generations to generate further51-710 RZ-derived spinach plants, and allowing seed of a 51-710RZ-derived spinach plant to form.

27. The method of paragraph 25 wherein a 51-710 RZ-derived spinach plantexhibits a combination of traits including medium-late bolting, asemi-erect to horizontal plant habit, a smooth to semi-savoy leafsurface and resistance to downy mildew (P. farinosa f. sp. spinaciae)races Pfs1 to Pfs15.

28. A spinach seed produced by the method of any of the paragraphs 25,26 or 27.

29. A spinach plant grown from the seed of paragraph 28.

30. The spinach plant of paragraph 10 wherein said combination of traitsfurther comprises medium ovate mature leaves.

31. A seed of the plant of paragraph 10.

32. A part of the plant of paragraph 10, wherein said part of the plantis suitable for sexual reproduction.

33. A part of the plant as described in paragraph 32, wherein said partcomprises a microspore, pollen, an ovary, an ovule, an embryo sac or anegg cell.

34. A part of the plant of paragraph 10, wherein said part of the plantis suitable for vegetative reproduction.

35. A part of the plant as described in paragraph 34, wherein said partcomprises a cutting, a root, a stem, a cell or a protoplast.

36. A seed of hybrid spinach variety 51-710 RZ, a sample of seed of saidhybrid variety having been deposited under NCIMB Accession Number 42336.

37. A plant grown from the seed of paragraph 36.

38. The spinach plant of paragraph 37, which is a plant grown from seedhaving been deposited under NCIMB Accession Number 42336.

39. A spinach plant, or a part thereof, having all the physiological andmorphological characteristics of the spinach plant of paragraph 37.

40. A part of the plant of paragraph 37, wherein said part is amicrospore, pollen, an ovary, an ovule, an embryo sac, an egg cell, acutting, a root, a stem, a cell or a protoplast.

41. A tissue culture of regenerable cells or protoplasts from the plantpart of paragraph 40.

42. The tissue culture as claimed in paragraph 41, wherein said cells orprotoplasts of the tissue culture are derived from a leaf, pollen, anembryo, a cotyledon, a hypocotyl, a meristematic cell, a root, a roottip, an anther, a flower, a seed or a stem.

43. A spinach plant regenerated from the tissue culture of paragraph 41,wherein the regenerated plant expresses all of the physiological andmorphological characteristics of hybrid spinach variety 51-710 RZ, asample of seed of said hybrid having been deposited under NCIMBAccession Number 42336.

44. A method of vegetatively propagating a plant of hybrid spinachvariety 51-710 RZ comprising the steps of: (a) collecting tissue capableof being propagated from a plant of hybrid spinach variety 51-710 RZ,representative seed of said hybrid spinach variety having been depositedunder NCIMB Accession Number 42336; and (b) producing a rooted plantfrom said tissue.

45. A method of producing a spinach seed, comprising crossing the plantof paragraph 37 with itself or a second spinach plant.

46. A spinach seed produced by the method of paragraph 45.

47. A spinach plant grown from the seed as defined in paragraph 46.

48. A method for producing a seed of a hybrid spinach variety 51-710RZ-derived spinach plant comprising the steps of: (a) crossing a spinachplant of hybrid spinach variety 51-710 RZ, representative seed of whichhaving been deposited under NCIMB Accession Number 42336, with a secondspinach plant or with itself; and (b) allowing seed of a 51-710-derivedspinach plant to form.

49. The method of paragraph 48, further comprising the steps of: (c)selfing the plant grown from said 51-710 RZ-derived spinach seed orcrossing it to a second spinach plant to yield additional 51-710RZ-derived spinach seed; (d) growing said additional 51-710 RZ-derivedspinach seed of step (c) to yield additional 51-710 RZ-derived spinachplants; and (e) repeating the crossing and growing steps of (c) and (d)for an additional 3-10 generations to generate further 51-710 RZ-derivedspinach plants, and (f) allowing seed of a 51-710 RZ-derived spinachplant to form.

50. A spinach seed produced by the method of claim 48 or 49.

51. A spinach plant grown from the seed of paragraph 50.

52. A method of producing a plant of spinach hybrid variety 51-710 RZcomprising at least one new trait, the method comprising introducing amutation or transgene conferring the at least one new trait into a plantof hybrid spinach variety 51-710 RZ, wherein a sample of seed of saidvariety has been deposited under NCIMB Accession Number 42336.

53. The spinach plant produced by the method of paragraph 52.

54. A method of producing spinach leaves comprising: (a) obtaining aplant according to paragraph 37, wherein the plant has been cultivatedto obtain leaves; and (b) harvesting spinach leaves from the plant tothereby obtain harvested spinach leaves.

55. The method of paragraph 54 further comprising packaging theharvested spinach leaves as a fresh vegetable.

56. The method of paragraph 54 further comprising processing theharvested spinach leaves as a processed food.

57. A container comprising one or more spinach plants of paragraph 37for harvest of leaves.

58. A method of determining the genotype of a plant of hybrid spinachvariety 51-710 RZ, representative seed of which has been deposited underNCIMB Accession Number 42336, or a first generation progeny thereof,comprising obtaining a sample of nucleic acids from said plant andcomparing said nucleic acids to a sample of nucleic acids obtained froma reference plant, and detecting a plurality of polymorphisms betweenthe two nucleic acid samples, wherein the plurality of polymorphisms areindicative of hybrid spinach variety 51-710 RZ and/or give rise to theexpression of any one or more, or all, of the morphological andphysiological characteristics of hybrid spinach variety 51-710 RZ asdefined in paragraph 37.

59. The method of paragraph 58 additionally comprising the step ofstoring the results of detecting the plurality of polymorphisms on acomputer readable medium, or transmitting the results of detecting theplurality of polymorphisms.

60. A plant of spinach hybrid variety 51-710 RZ comprising a transgeneconferring a desired trait, a sample of seed of said variety has beendeposited under NCIMB Accession Number 42336.

61. A seed that produces the plant of paragraph 60.

Having thus described in detail preferred embodiments of the presentinvention, it is to be understood that the invention is not to belimited to particular details set forth in the above description as manyapparent variations thereof are possible without departing from thespirit or scope of the present invention.

1. A seed of hybrid spinach variety 51-710 RZ, a sample of seed of saidhybrid variety having been deposited under NCIMB Accession Number 42336.2. A plant grown from the seed of claim
 1. 3. The spinach plant of claim2, which is a plant grown from seed having been deposited under NCIMBAccession Number
 42336. 4. A spinach plant, or a part thereof, havingall the physiological and morphological characteristics of the spinachplant of claim
 2. 5. A part of the plant of claim 2, wherein said partis a microspore, pollen, an ovary, an ovule, an embryo sac, an egg cell,a cutting, a root, a stem, a cell or a protoplast.
 6. A tissue cultureof regenerable cells or protoplasts from the plant part of claim
 5. 7.The tissue culture as claimed in claim 6, wherein said cells orprotoplasts of the tissue culture are derived from a leaf, pollen, anembryo, a cotyledon, a hypocotyl, a meristematic cell, a root, a roottip, an anther, a flower, a seed or a stem.
 8. A spinach plantregenerated from the tissue culture of claim 6, wherein the regeneratedplant expresses all of the physiological and morphologicalcharacteristics of hybrid spinach variety 51-710 RZ, a sample of seed ofsaid hybrid having been deposited under NCIMB Accession Number
 42336. 9.A method of vegetatively propagating a plant of hybrid spinach variety51-710 RZ comprising the steps of: (a) collecting tissue capable ofbeing propagated from a plant of hybrid spinach variety 51-710 RZ,representative seed of said hybrid spinach variety having been depositedunder NCIMB Accession Number 42336; and (b) producing a rooted plantfrom said tissue.
 10. A method of producing a spinach seed, comprisingcrossing the plant of claim 2 with itself or a second spinach plant. 11.A spinach seed produced by the method of claim
 10. 12. A spinach plantgrown from the seed as claimed in claim
 11. 13. A method for producing aseed of a hybrid spinach variety 51-710 RZ-derived spinach plantcomprising the steps of: (a) crossing a spinach plant of hybrid spinachvariety 51-710 RZ, representative seed of which having been depositedunder NCIMB Accession Number 42336, with a second spinach plant or withitself; and (b) allowing seed of a 51-710-derived spinach plant to form.14. The method of claim 13, further comprising the steps of: (c) selfingthe plant grown from said 51-710 RZ-derived spinach seed or crossing itto a second spinach plant to yield additional 51-710 RZ-derived spinachseed; (d) growing said additional 51-710 RZ-derived spinach seed of step(c) to yield additional 51-710 RZ-derived spinach plants; and (e)repeating the crossing and growing steps of (c) and (d) for anadditional 3-10 generations to generate further 51-710 RZ-derivedspinach plants, and (f) allowing seed of a 51-710 RZ-derived spinachplant to form.
 15. A spinach seed produced by the method of claim 13 or14.
 16. A spinach plant grown from the seed of claim
 15. 17. A method ofproducing a plant of spinach hybrid variety 51-710 RZ comprising atleast one new trait, the method comprising introducing a mutation ortransgene conferring the at least one new trait into a plant of hybridspinach variety 51-710 RZ, wherein a sample of seed of said variety hasbeen deposited under NCIMB Accession Number
 42336. 18. The spinach plantproduced by the method of claim
 17. 19. A method of producing spinachleaves comprising: (a) obtaining a plant according to claim 2, whereinthe plant has been cultivated to obtain leaves; and (b) harvestingspinach leaves from the plant to thereby obtain harvested spinachleaves.
 20. The method of claim 19 further comprising packaging theharvested spinach leaves as a fresh vegetable.
 21. The method of claim19 further comprising processing the harvested spinach leaves as aprocessed food.
 22. A container comprising one or more spinach plants ofclaim 2 for harvest of leaves.
 23. A method of determining the genotypeof a plant of hybrid spinach variety 51-710 RZ, representative seed ofwhich has been deposited under NCIMB Accession Number 42336, or a firstgeneration progeny thereof, comprising obtaining a sample of nucleicacids from said plant and comparing said nucleic acids to a sample ofnucleic acids obtained from a reference plant, and detecting a pluralityof polymorphisms between the two nucleic acid samples, wherein theplurality of polymorphisms are indicative of hybrid spinach variety51-710 RZ and/or give rise to the expression of any one or more, or all,of the morphological and physiological characteristics of hybrid spinachvariety 51-710 RZ as claimed in claim
 2. 24. A plant of spinach hybridvariety 51-710 RZ comprising a transgene conferring a desired trait, asample of seed of said variety has been deposited under NCIMB AccessionNumber
 42336. 25. A seed that produces the plant of claim 24.